This invention relates to suspension of mechanical systems, both moving and stationary. More particularly, the invention relates to permanent magnetic male and female levitation supports.
One of the most important mechanical inventions in use today is the ball bearing. Ball bearings are used in thousands of devices and assist in the rolling, rotating, or sliding of surfaces and objects which are in contact with one another. These motions are possible because the surfaces and the objects can move relative to one another along the rolling surfaces. This, coupled with lubricants and mechanisms for holding the ball bearing in place, provides the ball bearings the freedom of motion needed for proper function while containing the required stability.
Three main themes exist in the prior art concerning ball bearings. The first concerns the reduction of excessive friction. Friction can lead to fretting of the ball bearings. A number of lubrication methods and new materials have been used to reduce friction. For instance, Gary Boyd invented a ball bearing that does not require lubricant as a result of the composite ceramic material. Boyd obtained U.S. Pat. No. 6,318,899, herein incorporated by reference, which discloses the improved physical qualities of the ceramic ball bearing. But, the ball bearing still requires a raceway and still has friction, both of which are largely mitigated using the present invention.
A second theme in the prior art concerning ball bearings is lubricant. There are two specific problems regarding lubricants. One problem concerns the method of lubricating the ball bearings and preventing subsequent leakage. The second lubricant problem is replenishing lubricant that is expended, before the ball bearings breakdown. One particularly interesting method of preserving lubricants in and around the ball bearings dates back to 1976. U.S. Pat. No. 3,977,739, herein incorporated by reference, incorporates a ferrolubricant that, when coupled with magnetic bearings or raceway assembly parts, concentrates lubricant and prevents leakage. Despite improved lubrication techniques, removal altogether of the physical contact point between ball bearings provides a better solution than lubricated parts.
A third and final theme in the prior art relating to ball bearings concerns the design of the raceway itself. One such raceway design is disclosed by Hiroshi Ishiguro et al. in U.S. Pat. No. 6,554,480, herein incorporated by reference. Raceways are designed to reduce the likelihood that ball bearings collide. The force among the ball bearings is equally distributed within the raceway to minimize potential collisions. But, none of these raceway improvements removes the rolling friction inherent in the design of ball bearings.
Magnetic levitation is a relatively new phenomenon and has roots in electromagnetic theory. In the earliest days of electromagnetic theory, it was thought that it was impossible to form a stable configuration of levitation magnets using forces only. In recent years, several improvements to magnetic levitation have made it possible to develop levitated or partially levitated devices using forces only.
The main design limitation of purely magnetically levitated devices is the functional power requirement. All applications, from magnetically levitated globes to magnetically levitated trains, require the use of some power to hold objects in place.
A recent improvement in magnetics involves the use of permanent magnets to stabilize devices that levitate or utilize magnetic attraction or repulsion for stability. For example, U.S. Pat. No. 5,584,367 to Elberto Berdut, herein incorporated by reference, describes the design of an automotive system that stabilizes an axle using a system of magnets. These magnets utilize both attraction and repulsion forces to provide stability within the system by maintaining the axle shaft in equilibrium. The system provides support and stabilization in one direction while depending on the stability of an independent support structure in the other direction. But, this device requires lubrication and mechanisms that allow sliding motion of different parts. The device is subject to part failure and wear associated with this motion. This problem is common among these devices.
Another example of a magnetic field used for stabilization is in U.S. Pat. No. 6,920,870, herein incorporated by reference, which discloses stabilization of an arrow shot by an archer. One of the magnetic fields in U.S. Pat. No. 6,920,870 is rotationally invariant, while the opposing magnetic field is not rotationally invariant. In fact, the opposing magnetic field is not arranged so as to produce an opposing force. The magnetic field is capable of holding the arrow up but does not provide stable mechanical support.
In addition to magnetic levitation, fluid-based bearing devices are also used to reduce friction between objects in close proximity. Fluids include all types of gases and liquids. But, the fluids require power to function. Regardless of the power requirement, fluid-based bearing devices have enabled the development of many devices that utilize fluids that flow from one object to another. Examples might include rolling balls or low friction tables.
The main limitations of the above-described devices is the energy required to pump the fluid and the additional structures that support the other technological devices (e.g., containment devices for fluid, filtration of fluids flowing, etc.).
Accordingly, there is a need for a non-contact permanent magnetic male and female levitation support. Such a levitation support should eliminate ball bearings to reduce machine complexity, failure points, and provide a low-friction alternative design. Further, there is a need for a levitation support that increases system efficiency while reducing power and thermal losses due to friction and physical contact of moving parts. Moreover, there is a need for a levitation support that eliminates any power requirement, despite power availability, and enables the use of magnetic levitation in areas where power is not available. The present invention fulfills these needs and provides other related advantages.